Astronaut on the Moon

Astronaut study looks at effects of space travel on eyesight

Image credit: Universal Pictures

Concerns over the impact that space travel has on astronauts’ sight has led Canadian scientists to develop a new way to measure the mechanics of the human eye and detect ocular damage.

“We must try to protect astronauts’ vision, because the negative repercussions of zero gravity provide clear cause for concern,” said Santiago Costantino, a professor at the University of Montreal.

Most astronauts who spend more than a month in space develop space flight-associated neuro-ocular syndrome (SANS), which mainly affects their optic nerves.

This condition can significantly reshape the eyeball and create folds on the retina. Once back on Earth, some astronauts heal in a few weeks, while others suffer from vision problems for years.

“The method we’ve developed to measure and assess ocular health as the potential to identify astronauts at risk of developing SANS symptoms that can negatively impact both their health and their mission’s chances of success,” Costantino said.

Since symptoms get worse the longer astronauts stay in space, this could be a major problem for planned three-year missions to Mars.

The non-invasive technology for measuring ocular rigidity involves measuring the volume of blood that enters the eye with every heartbeat. Rigidity is calculated based on changes in blood volume and pressure inside the eye.

“Since deformed eyeballs are common among astronauts once they’re back on Earth, our working hypothesis is that rigidity will influence how much the eye changes shape,” said researcher Mark Lesk. “In practical terms, a more resilient eye won’t experience as much deformation.”

To verify their hypothesis and see how the disease develops, the researchers will measure astronauts’ eyes on three separate occasions over the next several months: first in Houston before take-off, then during their mission at the International Space Station and once more when they’re back to Earth.

Since only a handful of astronauts are launched into space each year, the number of study participants is limited and the researchers therefore won’t publish their findings for two years.

Last month another team found that low gravity and spaceflight affects the operation of human heart cells, although they appear to mostly return to normal on return to Earth.

Sign up to the E&T News e-mail to get great stories like this delivered to your inbox every day.

Recent articles